Epithelial ovarian cancer (EOC) is the most frequent cause of gynecologic cancer-related mortality in women (Jemal, A., et al., Global cancer statistics. CA Cancer J Clin, 2011, 61(2): p. 69-90). It was estimated that in 2008 (the most recent year numbers are available), approximately 21,204 women were diagnosed and 14,362 women died of disease in the US (see, www.cdc.gov/cancer/ovarian/statistics/index.htm). It is estimated that approximately 190,000 new cases will be diagnosed and 115,000 women will die from ovarian cancer per year world-wide. While advances in chemotherapy have been made over the past three decades, the overall 5 year survival for advanced stage disease remains less than 35%.
Initial response rates of advanced ovarian cancer to the standard upfront paclitaxel and carboplatin treatment approach is 75%, with complete clinical response rates near 55%. Unfortunately over 75% of subjects with complete clinical response are destined to relapse and succumb to their disease (Coukos, G. and S. C. Rubin, Chemotherapy resistance in ovarian cancer: new molecular perspectives. Obstet Gynecol, 1998, 91(5 Pt 1): p. 783-92). For most subjects, ovarian cancer will recur within two years, with median time to progression of 20-24 months for optimally surgically cytoreduced subjects and 12-18 months for subjects with suboptimal reduction. Response rates to second line chemotherapy are significantly lower, between 15-30%, depending on the length of progression free survival and the number of previous treatments. Once ovarian cancer has recurred, it is not considered curable and progression to death is usually inevitable, despite aggressive chemotherapy strategies. These facts elucidate the enormous unmet need for the development of alternate therapies in ovarian cancer (Coukos, G. and S. C. Rubin, Gene therapy for ovarian cancer. Oncology (Williston Park), 2001, 15(9): p. 1197-204, 1207; discussion 1207-8; Coukos, G., et al., Immunotherapy for gynaecological malignancies. Expert Opin Biol Ther, 2005, 5(9): p. 1193-210; Coukos, G., M. C. Courreges, and F. Benencia, Intraperitoneal oncolytic and tumor vaccination therapy with replication-competent recombinant virus: the herpes paradigm. Curr Gene Ther, 2003, 3(2): p. 113-25).
Fallopian tube and primary peritoneal cancers have many molecular, histologic, clinical and etiologic similarities to epithelial ovarian carcinoma. More that 90% of fallopian tube cancers are serous adenocarcinomas, which are histologically indistinguishable from papillary serous ovarian carcinoma. Women, diagnosed with fallopian tube cancer and primary peritoneal cancer, are clinically treated using the same surgical and chemotherapeutic approach as epithelial ovarian cancer because of the similarities in their biological behavior (Benedet, J. L., et al., FIGO staging classifications and clinical practice guidelines in the management of gynecologic cancers. FIGO Committee on Gynecologic Oncology. Int J Gynaecol Obstet, 2000, 70(2): p. 209-62). Most of the hereditary and perhaps many of the sporadic ovarian cancers may in fact originate in the fallopian tube, further underlying similarities between the two tumors.
Immunotherapy is a form of cancer treatment that activates the immune system to attack and eradicate cancer cells. Cytotoxic T lymphocytes (“CTL”) are critical to a successful antitumor immune response. T cells that attack cancer cells require the presentation of tumor antigens to naïve T cells that undergo activation, clonal expansion, and ultimately exert their cytolytic effector function. Effective antigen presentation is essential to successful CTL effector function. Thus, the development of a successful strategy to initiate presentation of tumor antigens to T cells can be important to an immunotherapeutic strategy for cancer treatment.
With the clinical outcome of many types of cancers being from poor to lethal, there exists a significant need for the development of novel therapeutic treatments.